EP0211637A1 - Système d'antenne pour véhicule - Google Patents

Système d'antenne pour véhicule Download PDF

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Publication number
EP0211637A1
EP0211637A1 EP86305977A EP86305977A EP0211637A1 EP 0211637 A1 EP0211637 A1 EP 0211637A1 EP 86305977 A EP86305977 A EP 86305977A EP 86305977 A EP86305977 A EP 86305977A EP 0211637 A1 EP0211637 A1 EP 0211637A1
Authority
EP
European Patent Office
Prior art keywords
antenna
antenna system
vehicle
vehicle body
loop antenna
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP86305977A
Other languages
German (de)
English (en)
Other versions
EP0211637B1 (fr
Inventor
Junzo Ohe
Hiroshi Kondo
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyota Motor Corp
Original Assignee
Toyota Motor Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toyota Motor Corp filed Critical Toyota Motor Corp
Publication of EP0211637A1 publication Critical patent/EP0211637A1/fr
Application granted granted Critical
Publication of EP0211637B1 publication Critical patent/EP0211637B1/fr
Expired legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/27—Adaptation for use in or on movable bodies
    • H01Q1/32—Adaptation for use in or on road or rail vehicles
    • H01Q1/325—Adaptation for use in or on road or rail vehicles characterised by the location of the antenna on the vehicle
    • H01Q1/3291—Adaptation for use in or on road or rail vehicles characterised by the location of the antenna on the vehicle mounted in or on other locations inside the vehicle or vehicle body
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q7/00—Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop

Definitions

  • the present invention relates to an improved vehicle antenna system which can efficiently detect broadcast waves received by the vehicle body and transmit them to various onboard receivers.
  • antenna systems are essential for positively receiving broadcast and/or communication waves at various onboard receivers such as radios, TV's, car-telephones and others.
  • Antenna systems also have an important role in citizen band tranceivers as providing a communication between an automobile and the other stationary or movable station.
  • citizen band tranceivers providing a communication between an automobile and the other stationary or movable station.
  • vehicle antenna system will increasingly be important for vehicles standardized with various receivers.
  • a pole type antenna is known as one of the conventional vehicle antenna systems.
  • the pole antenna projects exteriorly from the vehicle body and exhibits a favorable performance of reception in its own way.
  • the pole antenna was always an obstruction in designs of vehicle body.
  • the pole antenna also is disadvantageous in that it may accidentally or intentionally be subjected to damage and in that the pole antenna may produce unpleasant noises during running at high speeds. Therefore, it was very desired to eliminate the pole antenna from the vehicle body.
  • the first reason is that the level of surface currents is not so high as expected.
  • the prior art attempted mainly to detect surface currents flowing on the roof panel of the vehicle body.
  • the level of surface currents is insufficient for the surface currents to be utilized as output signals of the antenna system.
  • Japanese patent Publication Sho 53-22418 discloses one of such proposals wherein an electric insulation is formed on the vehicle body at a location in which surface currents flow concentrically. Currents flowing between the opposite ends of the electric insulation are detected by a sensor. Although such a proposal provides practicable detection signals which are superior in S/N ratio, it requires a pickup construction which is not applicable to normal mass production for some reasons such as the provision of notch on a portion of the vehicle body and so on.
  • the prior art antenna systems for detecting surface currents induced on the vehicle body by broadcast waves were not necessarily successful.
  • the prior art does not solve problems associated with the pickup construction for efficiently detecting surface current induced on the vehicle body by broadcast waves and the pickup arrangement for obtaining practicable S/N ratios.
  • the prior art antenna systems of pickup type had reduced sensitivities of reception and particularly irregular sensitivities different from one frequency band to another.
  • the present invention provides a vehicle antenna system comprising a high frequency pickup disposed in close proximity to a marginal portion on the vehicle body, said high frequency pickup capable of detecting high frequency surface currents having a frequency equal to and higher than a predetermined level, said high frequency pickup including a loop antenna opposed to the marginal portion of the vehicle body, said loop antenna being connected in series with a capacitor.
  • a series resonance circuit is defined by the loop antenna and the capacitor.
  • the series resonance circuit causes a resonation with frequencies through an increased range of bands such that the reception can be provided at higher sensitivities.
  • the prior art antenna systems mainly intended to receive AM waves in the tendency of the times. Since AM waves have too large wavelengths, the prior art antenna systems could not receive the AM waves with a good sensitivity.
  • the inventors aim at such a dependency of frequency and intend to provide an antenna system which exclusively receives broadcast waves belonging to FM or higher frequency bands normally equal to or higher than 50 MHz.
  • the present invention provides a vehicle antenna system which can very efficiently receive broadcast waves by detecting surface currents on the vehicle body, as otherwise considered impossible in the prior art.
  • FIG. 6 there are shown surface currents I induced on the vehicle body B of conductive metal material at various locations by external waves W such as broadcast waves when they pass through the vehicle body B.
  • the present invention intends to receive only waves belonging to relatively high frequency bands equal to or higher than 50 MHz, for example, FM waves, TV waves and so on.
  • the present invention is characterized by measuring the organic distribution of currents for such particular high frequency bands and providing a pickup disposed on the vehicle body at a location whereat the density of surface currents becomes higher with less noise.
  • the distribution of surface currents on the vehicle body can be determined by the use of a computer simulation and also by actually measuring the intensity of surface currents at various locations on the vehicle body.
  • the present invention utilizes a probe constructed in accordance with the same principle as that of the high frequency pickup which will be described in more details. The probe is moved along the surface of the vehicle body while changing its orientation at each of the locations.
  • FIG. 7 illustrates the construction of such a probe P which comprises a casing 10 of conductive material for avoiding the penetration of external waves and a loop coil 12 housed within the casing 10.
  • the casing 10 is provided with an opening 10a through which a portion of the loop coil 12 is externally exposed.
  • the exposed portion of the loop coil 12 is disposed in close proximity to the surface of the vehicle body B such that the loop coil 12 can detect a magnetic flux created by the surface currents on the vehicle body.
  • the loop coil 12 is electrically connected with the casing 12 through a short-circuiting line 14.
  • the output terminal 16 of the loop coil 12 is electrically connected with a core 20 in a coaxial cable 18.
  • the loop coil 12 further includes a capacitor 22 electrically connected therewith.
  • the capacitor 22 serves to cause the frequency of the loop coil 12 to resonate with a desired frequency to be measured. As a result, the efficiency of the pickup can be improved.
  • the output of the probe P is amplified by a high frequency voltage amplifier 24 the output of which in turn is measured at a high frequency voltage meter 26.
  • the output voltage of the coil is recorded by an XY recorder 28 as a value at each of the locations on the vehicle body.
  • the XY recorder 28 also receives a signal indicative of that location from a potentiometer 30 such that the level of high frequency surface currents can be determined at that location on the vehicle body.
  • Figures 1 and 2 illustrate the high frequency pickup disposed in close proximity to the rearward portion of the roof panel.
  • FIG 2 there is shown a naked roof panel 32 of metal material which is connected with the rear window glass 36 through a rear window frame 34 serving as a marginal terminal for the roof panel 32.
  • the high frequency pickup 38 is disposed spaced from the marginal edge of the rear window frame 34 within a range represented by: 12 ⁇ 10 ⁇ 3 ⁇ (metres) where ⁇ is the wavelength of broadcast waves to be received.
  • the present invention is characterized by that the high frequency pickup 38 is in the form of an electromagnetic coupling type pickup comprising a casing 40 of plastic material and a loop antenna 42 housed within the casing 40, the loop antenna 42 being electrically connected in series with a capacitor 44.
  • a portion of the loop antenna 42 is externally exposed through a slit 40a formed in the casing 40 at one edge such that an external flux can efficiently be detected by the loop antenna 42.
  • Signals detected by the loop antenna 42 are taken out through a coaxial cable 52 via a BNC connector 50 and then transferred to various onboard receivers such as radio, TV and other receivers.
  • the casing 40 of the high frequency pickup 38 includes L-shaped brackets 46 and 48 at the opposite ends thereof.
  • the brackets 46 and 48 are used to positively position and mount the casing 40 on the marginal portion of the vehicle body.
  • the loop antenna 42 is in the form of a single winding antenna which is electrically insulated such that the antenna can be located in intimate contact with the rear window frame 34.
  • the loop antenna 42 can more intensively intersect a magnetic flux created by the surface currents on the vehicle body.
  • Figure 4 illustrates the characteristics of reception in antenna systems in which solid line represents the characteristics of reception in the antenna system according to the present invention while broken line shows the characteristics of reception in a conventional parallel resonance type pickup.
  • the characteristics of reception in the antenna system according to the present invention can cover an increased range of bands with an improved sensitivity in comparison with those of the parallel resonance type pickup.
  • the antenna system having the above arrangement can easily receive waves belonging to FM-TV frequency bands, that is, a range of frequency equal to 76 - 220 MHz in Japan without need of any external control.
  • the high frequency pickup 38 is reduced in thickness since it is made of only the loop antenna 42.
  • the small-sized BNC connector 50 is utilized to connect the antenna system with the coaxial cable 52. As a result, the total size of the antenna system can be reduced.
  • FIG. 5 shows a concrete circuit used in the illustrated antenna system, which will be described below with reference to both the connection and function thereof.
  • the outer conductive sheath of the coaxial cable 52 is grounded. Signals detected by the loop antenna 42 are transferred to a receiver 54 through the coaxial cable 52.
  • the receiver 54 includes an impedance matching circuit 56, an amplifying circuit 58 and an output selecting circuit 60.
  • the impedance matching circuit 56 includes a band pass filter 62 and a discharge tube 64.
  • the voltage of the capacitor 44 obtained from the loop antenna 42 is applied to the input of the band pass filter 62 the output of which in turn is connected with a parallel circuit consisting of the discharge tube 64 and a capacitor C3.
  • the discharge tube 64 functions to protect the circuit from electrostatic breakage due to static electricity, thunderbolt and so on.
  • the band pass filter 62 provides an impedance matching with the loop antenna 42. Signals subjected to such an impedance matching are amplified by the high frequency amplifying circuit 58.
  • the amplifying circuit 58 includes two-stage connected transistors Q1 and Q2 the outputs of which are supplied to the output selecting circuit 60 to generate voice outputs and others.
  • inductance L1 and L2 are peaking coils; resistors R2 and R3 are to stabilize the transistor Q1; R5 and R6 denote bias resistors; and C3 and C9 designate bypass capacitors.
  • the present invention provides the desired impedance matching and high frequency amplifying process for feeble signals detected by the loop antenna 42 such that waves belonging to an increased range of bands including FM or TV bands can more sensitively be received by the antenna system.

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  • Engineering & Computer Science (AREA)
  • Remote Sensing (AREA)
  • Details Of Aerials (AREA)
EP86305977A 1985-08-09 1986-08-01 Système d'antenne pour véhicule Expired EP0211637B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP175221/85 1985-08-09
JP60175221A JPH0642605B2 (ja) 1985-08-09 1985-08-09 自動車用アンテナ装置

Publications (2)

Publication Number Publication Date
EP0211637A1 true EP0211637A1 (fr) 1987-02-25
EP0211637B1 EP0211637B1 (fr) 1990-12-05

Family

ID=15992404

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86305977A Expired EP0211637B1 (fr) 1985-08-09 1986-08-01 Système d'antenne pour véhicule

Country Status (5)

Country Link
US (1) US4823141A (fr)
EP (1) EP0211637B1 (fr)
JP (1) JPH0642605B2 (fr)
CA (1) CA1262570A (fr)
DE (1) DE3675999D1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005001766A1 (fr) * 2003-06-30 2005-01-06 Gyros Patent Ab Determination du degre de confiance

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0286201A (ja) * 1988-09-21 1990-03-27 Harada Ind Co Ltd 自動車用ループアンテナ
US5686903A (en) * 1995-05-19 1997-11-11 Prince Corporation Trainable RF transceiver
US5699054A (en) * 1995-05-19 1997-12-16 Prince Corporation Trainable transceiver including a dynamically tunable antenna
US5751255A (en) * 1996-06-07 1998-05-12 Carter, Jr.; Philip S. Electrically small receiving antennas
US6600896B2 (en) * 1999-06-25 2003-07-29 Cocomo Mb Communications, Inc. Exciter system and excitation methods for communications within and very near to vehicles
US6891512B2 (en) * 2000-12-27 2005-05-10 Cocomo Mb Cojmmunications, Inc. Antenna
CA2545178A1 (fr) * 2003-11-17 2005-05-26 Sst Wireless Inc. Antenne de corps de machine
US7136683B2 (en) * 2004-03-23 2006-11-14 Honeywell International Inc. Surface acoustic wave sensor and radio frequency identification interrogator fixture
EP1795860B1 (fr) * 2004-09-28 2012-11-14 Aisin Seiki Kabushiki Kaisha Ensemble d'antenne et unité de poignée de porte
JP2006295876A (ja) * 2005-03-15 2006-10-26 Matsushita Electric Ind Co Ltd アンテナ装置およびそれを用いた無線通信機

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3717876A (en) * 1971-04-23 1973-02-20 Volkers Res Corp Ferrite antenna coupled to radio frequency currents in vehicle body
EP0181765A1 (fr) * 1984-11-06 1986-05-21 Toyota Jidosha Kabushiki Kaisha Système d'antenne pour véhicule automobile
EP0183523A2 (fr) * 1984-11-26 1986-06-04 Toyota Jidosha Kabushiki Kaisha Système d'antenne pour automobile

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2520986A (en) * 1947-10-22 1950-09-05 Motorola Inc Vehicular antenna system
US2575471A (en) * 1950-04-13 1951-11-20 Philco Corp Vehicular antenna system
US3210766A (en) * 1962-02-15 1965-10-05 Ralph O Parker Slot type antenna with tuning circuit
US3794997A (en) * 1971-09-30 1974-02-26 Toyota Motor Co Ltd Vehicle with apparatus for detecting potential collisions
US3961330A (en) * 1973-12-21 1976-06-01 Ross Alan Davis Antenna system utilizing currents in conductive body
US3972048A (en) * 1974-11-29 1976-07-27 Ross Alan Davis FM-AM windshield antenna
US4080603A (en) * 1976-07-12 1978-03-21 Howard Belmont Moody Transmitting and receiving loop antenna with reactive loading
JPS5334826A (en) * 1976-09-10 1978-03-31 Nippon Chem Ind Co Ltd:The Production of stabilized iron oxide pigment
JPS59195811U (ja) * 1983-06-15 1984-12-26 トヨタ自動車株式会社 車両用アンテナ装置
JPS60172804A (ja) * 1984-10-09 1985-09-06 Toyota Motor Corp 車両用アンテナ装置
US4717921A (en) * 1984-11-15 1988-01-05 Toyota Jidosha Kabushiki Kaisha Automobile antenna system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3717876A (en) * 1971-04-23 1973-02-20 Volkers Res Corp Ferrite antenna coupled to radio frequency currents in vehicle body
EP0181765A1 (fr) * 1984-11-06 1986-05-21 Toyota Jidosha Kabushiki Kaisha Système d'antenne pour véhicule automobile
EP0183523A2 (fr) * 1984-11-26 1986-06-04 Toyota Jidosha Kabushiki Kaisha Système d'antenne pour automobile

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005001766A1 (fr) * 2003-06-30 2005-01-06 Gyros Patent Ab Determination du degre de confiance
US7616791B2 (en) 2003-06-30 2009-11-10 Gyros Patent Ab Confidence determination

Also Published As

Publication number Publication date
US4823141A (en) 1989-04-18
CA1262570A (fr) 1989-10-31
JPH0642605B2 (ja) 1994-06-01
JPS6236902A (ja) 1987-02-17
DE3675999D1 (de) 1992-01-09
EP0211637B1 (fr) 1990-12-05

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